Question

Pls answer ques. 15

Answer 1

Given:
Equation of a travelling wave is given by
y(x, t) = 2.0 cos 2π (10t – 0.0080 x + 0.35)
which can be written as,
y(x, t) = 2.0 cos(20 πt – 0.016πx + 0.7 π )
Where,
Propagation constant, k = 0.016 π
Amplitude, a = 2 cm
Angular frequency, w = 20 π rad s-1
Phase difference is given by the relation,
Φ = kx = 2 π/λ …(1)
a) For x = 4m = 400 cm
Φ = 0.016 π× 400cm = 6.4 π rad
b) For x = λ/2
Φ = 2 π/λ × λ/2 = π rad
c) For x = 3λ/4
Φ = 2 π/λ × 3λ/4 = 3π/2 rad